Thermostat mechanism



Patented Feb. 3, 1931 UNITED sT-ATEsP-ATENT ol=.i?lci?.

' HAROLD D. EATON, or LA ron'rE, INiiI.aNA,-As,sIGNO1i. To BAs'rIAN-MORLEY co., or LAPOBTE, INDIANA, A CORPORATION or INDIANA Figs. 2 and 3,.5respectively,

mnnnxosrA'r xEOHANIsia Application mea J'u'n as, 192e. sei-iai No. 117,897.

This invention relates to a thermostat mechanism, more particularlyl a mechanism adapted to actuate a movable member in one direction or the other due to temperature changes of the medium surrounding the ther-` mostat element or elements.

One object of the invention is to provide an improved mechanism of this character that is simple and economical in construction.

Another object of the invention is to provide a mechanism of this character that is positive in operation and capable of control ling the movable element within or by reason of slight changes in the temperature of the medium to be controlled.` e

A further object of the invention is to construct a mechanism of this character in which an electric switch is operated, with a snap action to insure positive closing and opening without danger of arcing. i

Other objects of the invention will be apparent to those skilled in the art to which my invention relates from the following description taken in connection with the accompanying drawings, wherein Fig. 1 is a side elevation, with parts broken away, of, an electric heater having associate with it a my invention.

Fig. 2 is a fragmentary view of the thermostat mechanism, with the switch element in open position. y

Fig. 3 is a view similar ito Fig. 2, but showing the switch element in position to close the circuit.

Fig. 4 is a sectional view. v Fig. 5 is a lsection on the line 5-5 of Fig. 4. Figs. 6 and .7 are fragmentary views of enlarged.'

Fig. 8 is a section on the line 7-7 of Fig. 5. v

Fig. 9 is a section on the line 9-9 of Fig. 6.

In one application of the invention, the movable element controls an electric circuit.

In the preferred arrangement, the circuit encrgizes an electric heating unit mounted within a container for fluid, such as water, and the thermostat elements extend into the container (as shown in the drawings) or into thermostat mechanism embodying a. conduit or casing which' in turn is mounted in the container.

Referring t'o the drawings, wherein I have illustrated the preferred application of my invention, 1 indicates a tank or container for the fluid, such as water, dicates. a drain pipe. 3 indicates 'a supply piper leading into the container 1 from a suitable source and 4 indicates a discharge or outlet pipe connected. to a, service system (not shown). v5 indicates an electr-ic heating unit within and extending longitudinally of the to be heated. 2' in-v container 1, preferably suplported'in anddepending from the top lwa cates a riser Lsurrounding the heating unit,

open at its lower end and having outlet'porta` 7 at its upper end to permit of circulation of the fluid. 8 indicates the leads connected -in a well known manner with the electric supply mains.

No claim-is made to the'iuid heater herethereof. 6 indif in illustrated sinceit formsthe subject-matplication filed by me ter of a co-pending a une,.1926,.Serial No.

om the 17th day ofi16g615.

10`\indicates as an entirety the thermostat mechanism arranged to o erate a movable .memberksuchas a switch e ement of an lectric swit h,rto open and close the electric circuit to the heating unit 5 dependent upon the temperature of the water in the container 1, whereby vthe, water may be heated to a predetermined temperature and automatically maintained substantiall at that temperature without attention.

or container connected f the thermostat mechaformed of suitable or separate casin with the tank.v nism, 1-1 indicates a base,

material, such as brass or insulation, as desired, and secured to the body ortion of a boss 12 by screws 12a. The oss 12 is y preference, the` lthermostat elements extend into the tank 1,

but they may be arranged within a conduit y boss- 12, being secured therein in a manner which insures a liquid tight joint; the other thermostat element comprises a'rod preferably formed from material whosel coefficient by of expansion is lsubstantially Zero, at least within certain ranges of temperature, such as lava, porcelain, invar metal, or the like.

i The tube 13 and rod 14 are connected, preferably by suitable adjustable means, at their inner ends, whereby the expansion of the tube 13 serves to move the rod endwise toward the y opening 15 formed in the base 11 and is op `right as viewed in Figs. 2, 3, and 4, and the contraction of the tube 13 serves to move the rod 14 endwise in the opposite direction. The inner end of the rod 14 proJectsthrough an eratively connected with an operating means 16, preferably comprising a plurality oi? multiplying levers mounted in the manner to b'e later set forth'. 17. indicates a block of insulating material supported in rigid',` but spaced relation to the base 11, preferably-by rods 18 fixed at their opposite ends to the base and block in anyv desired manner. On its inner face, the block 17 supports a switch 19 comprisingv standards 19a, 196, to one of l which is pivotally connected the movable Aelement 19o adaptedto engage and `disengrage the other standard to close and open the electric circuit tothe heating unit 45. The Shanks of the standards 19a,f19b, extend through the block 17 and form' terminals 19 for the leadsSa, one being connected to one lead or ,terminal of the unit 5 and the other being connected to one of the supply mains so as tointerpose the switch 19 in the circuit'. The

multiplying levers16 may comprise a main lever 21 pivoted on a bracket 21a and a second lever 22 pivoted on the main lever 21. The main lever 21 preferably comprises la U-shaped member which straddles the second lever 22, the latter being pivoted between the side arms thereof, on a pivot 22a. The bracket 21a comprises a plate having upstanding arms which support the opposite ends of the pivot 23 for the lever 21. 24 indicates an abutment 'with which the lever 22 engages. As shown in the drawings, the thermostat rod 14 engages the lever 22 between the fulcrum 24 and thel pivot 22a on which the lever 22 is mounted, so that end- Y, wise or thrust movement of the rod 14 to-` ward the left will swing the lever 22 about the abutment 24 and the lever 22 will in turn swin the lever 21 about its pivot 23 to swing'4 the ee end of the latter toward the left.

p 25 indicates as an entirety the operatingconl formed witha -slot 29 in which is disposed the nections between thel lever 21 and the movable element 190 of the switch 19. Of the operating connections 25, 26 indicates a mem-- ber fixed to the switch element 19e in any desired manner, preferably by a screw 2,7, being insulatedtherefrom by a strip of insulation Amaterial 28. The member 26 is upper or free end of a rocker 30, vso that the sidewalls of the slot form tappets to be engaged by the rocker 30 and operated therelater be set, forth;" this arrangement being the lequivalent of a pivotal slidingconnection between the member 26 and rocker 30 to permit the free movement about their respective pivotal supports; The rocker 30 preferably comprises a substantially U-shaped member trunnioned in. any suitable manner at its oppositefends, upon the adjacent aligned .rods 18. 31 indicates acoiled sprin connected atone end to thefree end Yof t e lever 21 and at its other end to the upper portion of the, rocker 30, and normally tending to vswing the latter in one direction or the other, ac-

from one position to the other, as will 7l .cording to the'position of the lever 21, as i will later appear. Y v y IThe supports for the rocker 30 may comprise a pair of slotted blocks 30a fixed to the inner sides of the ro'ds'18 by screws 18a, and ,the lower ends of the rocker may be provided withknife edges that jrock on the bottom` walls of the slots 30a. By making thev rocker ofv U-s ape, provision is made for the free movementof the spring 31.

Asshown, the pivot for the lever 21 is preferably'disposed in a vertical plane coincident operate the rocker in the opposite direction.

As the rocker'30 is disposed within the slot 29, the side walls thereof are disposed in the path of movementA of its free end and therefore the member- 26 will be actuated by the rocker in one direction or the other according to the direction ofits movement. The slot 29 is preferably somewhat wider than the thickness of the rocker 30 so that whenv the lever 21 is actuated from one side of the axis of the pivots or trunnions for the rocker to the other side thereof, the influence ofthe spring will first impart to the rocker a certain' amount of momentum'so that it may strike the remote side wall of the slot 29 with a blow and thus operate the switch element 19a with a quick movement, either to open the circuit or to close it, with minimum danger of arcing. 32 indicates a stop for limiting the movement of the switch element 190 outwardly or in a direction to break the circuit, so that relatively slight movement of the free end of the lever 21 may eiiect operation of the switch element 190 in either direction. The stop 32 is preferably adjustable. For this purpose it may comprise a screw mount- "right, lI provide a coiled spring 33, which normally tends to swing the lever 21 toward the right, as viewed in Figs. 2, 3, and 4, to

open the switch 19. lThe spring 33 is pref-` erably a coiled spring and is interposed'between an abutment 34 and an element 35 that bridges the arms of the lever 21. By reference the abutment 34 comprises a yo e 34a mounted on the base 11 and straddling the levers 21 and 22, the end wall 346 of the yoke serving as the abutment for the coiled spring 33. This wall also serves as a support for the fulcrum 24. The fulcrum 24 comprises a rod 24 having a screw threaded portion extending through a threaded opening in theV end wall 346, whereby its rotation will effect adjustment of its inner end. Such adjustment will affect the action of the rod 14 in swinging the lever 21 to control vthe switch so that the temperature of the water in the container 1 will be maintained at a higher or lower degree, as' may be desired. The spring 33 is coiled around the rod24 so that the latter may serve to support it in position, and the bridge for the spring may comprise a washer or collar loosely mounted on the rod 24. The outer end of the rod 24l is shaped t'o receive a .suitable tool to adjust its inner end. The outer end of the rod 24 may carry an indicating arm 35, which moves relative to graduations on the front wall of the Acasing 36 so that such adjustment can be readily determined. The casing 36 en- 'closes the switch 19 and operating means 16,

but is preferably cut away to receive Ithe block 17 to ex ose' the terminals 19.

Operation: i 2 showsthe normal position of the switc member 119e and elements of the operating means 16 when the water in the container 1 is at or above the predetermined degree of temperature, with the rod 14 at its extreme-right position. The spring y33 acting on the lever 21 yieldingly maintains it in its inner position and the lever, in turn, through the spring 31, maintains the rocker 30 in its inner position, thus holding the switch 19 open. I now the temperature of the water in the container 1 drops due to cooling or the disch arge of heatedwater therefrom and is replaced with cold water from the pipe 3, the tube 13 will contract and effect endwise outward movement of the rod 14. The rod 14 will in turn act on the lever 22, swinging its lower end about the inner end of the rod 24. The lever 22 will in turn swing the lever 21 about the pivot ,23 and move the spring 33 to the otherside of the axis on which the rocker 30 swings.-

As a' result, the free end of the rocker will be operated outwardly, strike the opposite or remote side wall of the slot 29 and swing the switch element 19e to its circuit closing posi-y tion with a quick,vsnap action, thus closing the circuit tothe heating unit. When the water has been heated to the predetermined temperature, these parts will move in the opposite direction and open the electric circuit.

To those skilled in the art to which my invention relates, many changes in construction and widel diering embodiments and applications o the invention will suggest themselves without departing from the sp'irit and scope thereof. 'Mydisclosures and the description herein are purely illustrative and are not intended to be in any sense limiting. What I claim is: `v

1.l Inmechanism of the class described, the

combination with a support and a member movably mounted thereon, of a plurality of operatively .connected'levers, means normally acting on one terminal'lever to move it in one direction, means arranged to act on the other terminal lever to move the first mentioned terminal lever in thev opposite direction, a member'pivoted at its oppositeends on said suppoit on an axis transverse to and intermediate the travel of said first mentioned' terminal lever, said pivoted' member bein operatively connected to said movable mem r, and a spring between and connected at its ends to said pivoted member and first mentioned terminal lever and operatedby the latter to effect movement of said pivoted member from one side of its axis to the other side thereof.

2. In mechanism ofthe class described, the combination with a support and -a member movably mounted thereon, of a plurality of operatively connected levers, means normally acting on one terminal lever to move it in one direction, means arranged to act on the other terminal lever to move the first mentioned terminal lever in the op osite direction, a U-shaped member pivot at its opposite ends on said support on an axis trans- .ver'se to and at opposite sides of said 'lrst mentioned terminal lever and intermediate the travel thereof, said U-member being o ratively connected to said movable mem er, j

and a spring between and connected at its ends to said U-member and first mentioned terminallever and operated by the latter to effect movement of said U-member from one on said support and having its intermediate y I portion disposed between said tappets and 'alternately engageable therewith to operate said movable member, a lever s'wingable in a,

plane between the ends of said U-member to either side of the axis of the` pivots therefor, a coiled expansion spring between and connected at its opposite ends to the central por- 'tion of saidU-member and said lever, wherescribed my name.

'by the latter carries the adjacent end of the spring to either side of the pivots for said U- member and effects movement of the latter from one position to the other, and vseparate mea-ns for moving said lever in opposite directlons.

In testlmony whereof, I have hereunto sub- HAnoLD D. EATON. 

